Last year, Lindsay and I had the privilege of undertaking Advanced Fertility Training with the highly respected, Leah Hechtman. Throughout the course, we explored the many facets of fertility and conception, delving into both natural and assisted reproductive approaches.

One area that particularly captured our interest was the role of sperm health in recurrent pregnancy loss (RPL). While much of the focus in fertility discussions is placed on female factors, emerging research highlights the significant impact of sperm quality on pregnancy outcomes. In this article, we explore key paternal factors linked to RPL and share evidence-based nutrition and lifestyle strategies to optimise sperm health.Understanding the role of sperm DNA fragmentation (SDF) - a measure of sperm genetic integrity - in RPL.

What is Recurrent Pregnancy Loss (RPL)?

RPL can be a deeply distressing experience for couples trying to conceive. While much of the focus has traditionally been on female factors, emerging research highlights the significant role of SDF and other paternal factors in pregnancy outcomes. Understanding these male fertility factors can enhance clinical practice, patient counselling, and targeted interventions for couples experiencing RPL.

RPL is defined as two or more consecutive pregnancy losses before 20 weeks of gestation. Globally, around 15% of recognised pregnancies end in miscarriage. While maternal age and health conditions are well-documented contributors, recent research has shown that advanced paternal age and sperm health also influence pregnancy outcomes.

Understanding the Role of Sperm Health in Recurrent Pregnancy Loss

When it comes to fertility and pregnancy loss, much of the focus has traditionally been placed on female factors. However, emerging research highlights the significant role that sperm health plays in conception and pregnancy outcomes, particularly in cases of RPL. While RPL has often been linked to maternal health, growing evidence suggests that factors such as SDF, paternal age, and overall sperm quality can also contribute.

The Link Between Sperm Health and Pregnancy Loss

Advanced paternal age, typically over 40, has been associated with a greater risk of miscarriage. This may be due to an increase in sperm DNA damage, chromosomal abnormalities, and oxidative stress.

SDF has been found to be higher in men whose partners experience RPL. Elevated SDF levels can impact embryo quality, implantation success, and pregnancy viability, increasing the likelihood of miscarriage even when fertilisation occurs.

Factors contributing to SDF include:

Age-related DNA methylation changes (see our methylation article for more information on this)
Oxidative stress and inflammation (stress, over-excerising, alcohol, medication etc)
Lifestyle habits such as smoking, alcohol, and poor diet
Environmental toxins and radiation exposure

Key Research Findings on SDF and RPL

1. Paternal Age and RPL - A meta-analysis by Du Fossé found that fathers aged 40-44 years had a 23% higher risk of miscarriage compared to younger fathers. This association was particularly strong in first-trimester miscarriages.

2. SDF and Pregnancy Outcomes - A study by Borges analysed 475 intracytoplasmic sperm injection (ICSI) cycles, revealing that couples with SDF levels ≥30% had significantly poorer embryo quality, lower implantation rates, and a 2.5-fold increase in miscarriage risk.

3. Systematic Reviews Confirming SDF's Role - McQueen reviewed 13 studies, finding significantly higher SDF rates in men whose partners had RPL.

How Can Men Improve Sperm Health?

While some factors influencing SDF are genetic, the good news is that is most cases, sperm parameters are modifiable through lifestyle changes and can be improved over 3 months.

Here are some evidence-based strategies that you can include to improve sperm quality:

✅ Increase Antioxidants: A diet rich in vitamin C, vitamin E, zinc, and selenium can reduce oxidative stress on sperm.

✅ Maintain a Healthy Weight: Obesity is linked to hormonal imbalances and lower sperm quality. If your BMI is over 26 (assuming you do not have excess muscle mass) is it worth looking into dietary changes to reduce BMI and improve body composition.

✅ Reduce Environmental Toxins: Limit exposure to pesticides, plastics (BPA), and heavy metals. These are found in plastic bottles, takeaway containers, personal care products, detergents etc. Opt for natural products where possible. Wash fruit and vegetables thoroughly before consumption.

✅ Manage Stress and Sleep: Chronic stress and poor sleep can increase cortisol levels, negatively impacting testosterone and sperm health. Try and go to sleep and wake at the same time every day. The more consistent your sleep patterns, the better your circadian rhythm which can help with hormone balance amongst many other benefits.

✅ Exercise Regularly: Moderate exercise improves testosterone levels and sperm motility.

✅ Avoid Smoking and Excess Alcohol: Both contribute to higher SDF and lower fertility potential.

Where to Get Help in the UK

If you or your partner are experiencing RPL, seeking specialist care can make a difference. Here are some top UK clinics and resources:

Tommy’s National Centre for Miscarriage Research – A leading research hub offering support and guidance for pregnancy loss.
The Lister Fertility Clinic – Specialising in male fertility assessments, sperm DNA fragmentation testing, and advanced fertility treatments.
London Sperm Bank – Offers advanced semen analysis and cryopreservation services.
CARE Fertility – One of the UK’s largest fertility clinic networks, providing comprehensive male fertility testing.
NHS Fertility Services – Information on NHS fertility treatments, eligibility, and referrals.

Final Thoughts

While maternal age remains a critical factor in RPL, sperm quality and DNA integrity are increasingly recognised as key contributors. Couples experiencing recurrent miscarriage should consider a comprehensive fertility assessment for both partners.

As research evolves, integrating sperm DNA fragmentation testing into your fertility care may improve pregnancy outcomes and give you better clarity from the start.

If you’re navigating fertility challenges, seeking expert guidance and making lifestyle changes could be crucial steps toward a successful pregnancy. Don’t hesitate to reach out to find our more about our fertility packages.

The Role of Sperm in Pregnancy Loss